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Health by the Numbers: 6 Key Findings from 2016

6 Key Findings from 2016

doctor, stethoscope

(Image credit: NPFire/

Are there more or fewer doctors than ever before? How many people are really smoking weed? Are people opting for the flu vaccine in greater numbers? Live Science looked into these questions and others by reviewing key data from 2015 and 2016, scouring for trends in health and medicine. Here are six of our findings:

The percentage of Americans who use marijuana has increased.

Marijuana plants

(Image credit: OpenRangeStock/Shutterstock)

Are more Americans smoking marijuana than ever before? Yes, but the change may not be drastic — a recent confidential Gallup poll found that 13 percent of Americans said they currently smoke marijuana. That's up from 11 percent of Americans in 2015, and 7 percent of Americans two years prior, in 2013.

Some research suggests that more people may be smoking marijuana because they view it as less harmful than people did in the past. A study published in August in the journal The Lancet Psychiatry showed that concerns about the risk of marijuana dropped between 2002 and 2014.

"The National Institute on Drug Abuse is supporting a great deal of work in states and in regions of the country that have experienced the biggest legal and social changes, so we can begin to understand what does the changing social environment lead to in terms of health effects or health issues," said Dr. Wilson Compton, deputy director at the National Institute on Drug Abuse and lead author of the study. [3 More States Legalize Recreational Use of Marijuana: How the Map Looks Now]

The number of mass shootings remained about the same.

bullet holes in glass

(Image credit: Bullet holes photo via Shutterstock)

According to the Gun Violence Archive, the number of mass shootings in the U.S. in 2016, as of Dec. 13, was 367 —  slightly fewer than the 372 mass shootings in 2015, with about two weeks left in the year to go. (A mass shooting is broadly defined by the Gun Violence Archive as one in which at least four people are killed or injured.)

The deadliest incident by far was the June 12 shooting at an Orlando nightclub,where 49 people were killed and 53 others were wounded.

Researchers are increasingly looking at shooters' behavior rather than their ideologies in order to help prevent such attacks. One studyfound that 83 percent of shooters who acted alone had hinted to others about their plans before becoming violent, said Mia Bloom, a professor of communication at Georgia State University who studies suicide terrorism.

"There is no template," Bloom told Live Science in June, in the days after the Orlando shooting. "What we're seeing more and more is that the logical, normal sequence is out of whack."

Teen drug use is down.

marijuana, joint, smoking, woman

(Image credit: Stanimir G.Stoev | )

The 2016 Monitoring the Future annual survey, released by the National Institutes of Health, showed that drug use among teens has dropped over the past year for certain substances.

In 2015, 1.8 percent of teenagers reported having used cocaine in the past year, compared with 1.3 percent in 2016. Among eighth-graders, past-year use of inhalants, such as spray paints and glues, dropped from 4.6 percent in 2015 to 3.8 percent in 2016, and past-year use of MDMA (ecstasy) dropped from 1.4 percent to 1.0 percent. Furthermore, the past-year use of the prescription drugs Vicodin and OxyContin plummeted among 12th-graders, from 9.7 percent and 4.3 percent, respectively, in 2015 to 2.9 percent and 3.4 percent, respectively, in 2016.

For marijuana, past-year use among eighth-graders dropped from 11.8 percent in 2015 to 9.4 percent in 2016. Among 10th- and 12th-graders, the rates were relatively stable, at around 24 percent and 36 percent, respectively, in 2016. These findings from the Monitoring the Future survey are in line with those of another study published this year in the journal Drug and Alcohol Dependence, which found that pot use among adolescents and young adults has remained steady not just in the past year, but in the past decade, despite the passage of medical marijuana laws.

Flu vaccination rates are down.

Flu shot being injected into patient.

(Image credit: AZP Worldwide |

Surveys from the Centers for Disease Control and Prevention show that the rate of flu vaccinations dropped in American adults between 2015and 2016. Based on data from January to June of each year, Americans in three age groups — 18 to 49, 50 to 64, and 65 and older — all had lower rates of flu shots in 2016 than in 2015. [Flu Shot Facts & Side Effects (Updated for 2016-2017)]                      

For Americans ages 18 to 49, the percentage who received a flu shot dropped from 32.9 percent in 2015 to 31.6 percent in 2016, according to CDC statistics. For Americans ages 50 to 64, the percentage dropped from 49.1 percent to 45.4 percent. For Americans 65 and older, the rate declined from 71.7 percent to 69.4 percent.

The U.S. has more medical residents than ever before.

Medical students, human anatomical research

Thanks to student-centered learning, medical graduates were ill-equipped to specialise. (Image credit: Mercy Health, CC BY-SA)

In March of this year, thousands of fourth-year medical students received their residency placements, dictating where they would spend the next few years of their life and which residency program they would enter. According to data from the National Resident Matching Program, the number of allopathic medical school seniors who were entering a residency in the United States in 2016 grew by 221 from 2015, to 18,668 — or about 1.2 percent. (Allopathic medical students earn an MD, as opposed to other medical degrees, such as DO.)

The percentage of Americans without health insurance dropped.

President Obama at Kennedy Space Center

President Barack Obama delivers a speech about his vision for the future of space exploration at Kennedy Space Center in Cape Canaveral, Florida, on April 15, 2010. (Image credit: NASA/Bill Ingalls)

The percentage of Americans who did not have health insurance in the fourth quarter of 2016 was 8.6 percent, down from 9.1 percent at the same time last year, according to data from the National Health Interview Survey.

In July, President Barack Obama authored a scientific article in the medical journal JAMA analyzing the results of the Affordable Care Act. While Obama acknowledged the success in the drop of uninsured Americans, he also wrote that "Despite this progress, too many Americans still strain to pay for their physician visits and prescriptions, cover their deductibles, or pay their monthly insurance bills." He also recommended policies that could reduce the cost of prescription drugs, and encouraged Congress to consider a government-run insurance plan that would compete in the insurance marketplace.

Originally published on Live Science.